Synchronizer for transmission

Abstract

Balls to be moved radially outward by a centrifugal force are held in a clutch hub, and projections extending around the outer circumferences of the balls are united with a synchronizer ring. Those portions of the projections, which radially confront the balls, are formed with slopes for establishing an axial force to push the synchronizer ring away from the spline piece on the basis of the centrifugal force of the balls. Thus, the axial force for disengaging the synchronizer ring from a rotating member to be synchronized can be increased to prevent the chatter at a low number of revolution and to effectively eliminate the drag torque at a high number of revolution.

What is claimed is: 
     
       1. A synchronizer for a transmission, in which a hub sleeve having a splined inner circumference is axially movably arranged on an outer circumference of a clutch hub mounted on a rotating member, in which keys are arranged between said clutch hub and said hub sleeve, in which a synchronized rotating member splined to said hub sleeve as said hub sleeve is axially moved is arranged adjacent to said clutch hub and rotatably with respect to said rotating member, in which at least one synchronizer ring brought into frictional contact with said synchronized rotating member for transmitting a torque thereto is arranged between said synchronized rotating member and said clutch hub, and in which said synchronizer ring is formed in its outer circumference with a chamfer to be splined to said hub sleeve, the synchronizer comprising: an inertial mass held by said clutch hub so that the inertial mass can be moved only radially outward by a centrifugal force;   a projection extending around an outer circumference of said inertial mass and united with said synchronizer ring; and   a slope formed on said projection at a portion radially confronting said inertial mass for generating an axial force for pushing said synchronizer ring away from said synchronized rotating member on a basis of the centrifugal force of said inertial mass.   
     
     
       2. A transmission synchronizer according to claim 1, wherein said projection has a leading end portion folded toward a radial center of said synchronizer ring and formed with said slope on an inner surface thereof. 
     
     
       3. A transmission synchronizer according to claim 1, wherein said clutch hub is formed in its outer circumference with a recess which extends radially of said clutch hub and is opened in the outer circumference of the clutch hub for accommodating said inertial mass.   
     
     
       4. A transmission synchronizer according to claim 1, wherein said inertial mass includes a steel ball. 
     
     
       5. A transmission synchronizer according to claim 1, wherein said inertial mass includes a plurality of balls arranged at an equal interval in a circumferential direction of said clutch hub.   
     
     
       6. A transmission synchronizer according to claim 5, wherein said inertial mass includes three steel balls arranged at an equal interval in the circumferential direction of said clutch hub.   
     
     
       7. A transmission synchronizer according to claim 5, wherein said projection includes a plurality of rectangular plate portions formed at an equal interval in the circumferential direction of said clutch hub.   
     
     
       8. A transmission synchronizer according to claim 7, wherein said projection includes three rectangular plate portions formed at an equal interval in the circumferential direction of said clutch hub.   
     
     
       9. A transmission synchronizer according to claim 1, further comprising an elastic member arranged between said clutch hub and said synchronizer ring for pushing said synchronizer ring toward said synchronized rotating member.   
     
     
       10. A transmission synchronizer according to claim 9, wherein said elastic member includes a ring-shaped wave spring.   
     
     
       11. A transmission synchronizer according to claim 1, wherein said synchronized rotating member includes: a gear fitted on said rotating member; and a spline piece splined on a boss portion of said gear and formed with said chamfer in its outer circumference.